Resistance of Several Hibiscus cannabinus genotypes Against Meloidogyne incognita

Resistance of Several Hibiscus cannabinus genotypes Against Meloidogyne incognita   Kenaf (Hibiscus cannabinus) is known as a source of natural fibers. Infection of Meloidogyne incognita (root-knot nematode) in kenaf plants causes stunting of plants, thereby reducing crop production. This study aimed to determine the resistance of seven kenaf genotypes against M. incognita. The experiment was conducted by infesting kenaf plants aged 15 days after planting (DAP) with M. incognita in a population of 40 juvenile nematodes 2 per 100 g of soil. The planting medium used was sandy soil with a composition of 55% sand, 36% dust, and 17% clay. The resistance variable consisted of root knot index and nematode reproduction factors. Analysis of salicylic acid, phenol, lignin and several plant growth variables were carried out at 75 DAP. Among the seven kenaf plant genotypes evaluated, there were 3 tolerant genotypes (KR4, KR15 and KR5) and 4 highly susceptible genotypes (KR1, KR6, Kin2, and DS028). Genotypes that had a tolerant response to M. incognita showed an increase in phenolic compounds, salicylic acid, and lignin in the roots compared to the control. The decrease in plant height, crown fresh weight, and root fresh weight varied due to M. incognita infection.Kenaf merupakan salah satu tanaman yang menghasilkan serat alam. Infeksi Meloidogyne incognita (nematoda puru akar) pada tanaman kenaf menyebabkan tanaman kerdil sehingga menurunkan produksi tanaman. Penelitian ini bertujuan menentukan ketahanan tujuh genotipe kenaf terhadap M. incognita. Percobaan dilakukan dengan menginfestasi tanaman kenaf yang berumur 15 hari setelah tanam (HST) dengan M. incognita pada populasi 40 nematoda juvenil 2 per 100 g tanah. Medium tanam yang digunakan ialah tanah berpasir dengan komposisi pasir 55%, debu 36%, dan liat 17%. Variabel ketahanan terdiri atas indeks puru akar dan faktor reproduksi nematoda. Analisis asam salisilat, fenol, lignin serta beberapa variabel pertumbuhan tanaman dilakukan pada umur tanaman 75 HST. Diantara tujuh genotipe tanaman kenaf yang dievaluasi terdapat 3 genotipe yang toleran (KR4, KR15 dan KR5) dan 4 genotipe sangat rentan (KR1, KR6, Kin2, dan DS028). Genotipe yang memiliki respons toleran terhadap M. incognita menunjukkan peningkatan senyawa fenol, asam salisilat, dan lignin pada akar dibandingkan dengan kontrol. Penurunan tinggi tanaman, bobot segar tajuk, dan bobot segar akar bervariasi akibat infeksi M. incognita